robert78.5

When I plug a 9007 bulb into my truck it is dimmer than my 9004. Should it not be brighter?

Diesel Dave2

Rob.....I bet you need the heavy duty harness with the relays to get full power and get rid of voltage drops through the DLM and light switch.The 9007 pull even more power...We are working on a home made harness and will be ordering the heavy duty sockets with 12 gauge wire...We are going to see if we could burn down Mike H truck..

torquefan

No, a 9007 bulb is marginally higher wattage than a 9004, but they are not directly interchangeable. For one thing, the filament positioning is completely different and would not work with that lense. Most importantly the connector pinout is different between the 9004 and 9007. One uses the center pin for ground, while the other uses one of the end pins.

I don't think the 10 watt improvement would ever be noticeable anyway.

robert78.5

I converted to dual light system with harness. Worked great until i went on a holiday and drove some long hours. It started when the high beam indicator would stay on even when headlight switch was turned off. Than the next night headlights would stay on when headlight switch turned off. I had to pull fuses on harness to get headlights off. I found fuse burnt for right headlight in truck main fuse box. I replaced fuse and plugged original harness to one bulb on each side and everything works good. One relay on quad harness
was starting to melt the plug. I like the four bulb system, just have to figure out the right way to put relays.

robert78.5

Ok that makes sense, i thought the wiring was the same on both bulbs. I tried to rewire the harness yesterday and got nowhere. Does anyone have the correct pin locations for each bulb. 9004 and 9007. Thanks

Diesel Dave2

Your getting a power loss even with the 9004 ,with the standard setup....The relays will put power from the battery instead of through the switch..But it also looks like you need heavier gauge wire for this...